technology is advanced. they're going the start as close as possible to the event, to the explosions and move out from there. so, my nat data first and then slowly but surely, they'll get through the rest of those photos and video. over time, but it will be weeks. they will have a better sense of what might be connected to other factors, like the bags that they think carried the bombs. so i think it's great, get this now, because it's difficult to be preserved. >> is this, is that an approach that has evolved over the past 12 years? is that not the way they would have approached this before 9/11? before we had this huge investment in intelligence since then? >> first, we simply didn't have access to all this video and photo technology that is ubiquitous today. there are far more video cameras, hoemts and restaurants and people are walking around with iphones. the second is a much greater ability to deal with these massive amounts of data and the technology there has improved and the u.s. government and the i